The sheep bot fly (Oestrus ovis) is a pest of domesticated sheep worldwide. This fly is an obligate parasite and the larval stages inhabit the sinus cavities of the host. The adult fly does not lay eggs, but rather ejects first-stage larvae at the noses of sheep, occasionally targeting humans in close proximity to sheep, although the fly cannot complete development in a human. The pest can cause economic losses, most commonly in tropical and Mediterranean regions.